Department of Biological Sciences, College of Arts and Sciences, Mississippi State University, Starkville, Mississippi.
Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, Mississippi.
Environ Toxicol. 2019 Oct;34(10):1149-1159. doi: 10.1002/tox.22817. Epub 2019 Jul 16.
Exposure to environmental contaminants and consumption of a high, saturated fatty diet has been demonstrated to promote precursors for metabolic syndrome (hyperglycemia, hyperinsulinemia, and hypertriglyceridemia). The purpose of this study was to determine if exposure to the most prevalent environmental persistent organic pollutants (POPs) would act as causative agents to promote metabolic syndrome independent of dietary intake. We hypothesized that POPs will activate the advanced glycated end-product (AGE)-and receptor for AGE (RAGE) signaling cascade to promote downstream signaling modulators of cardiovascular remodeling and oxidative stress in the heart. At 5-weeks of age nondiabetic (WT) and diabetic (ob/ob) mice were exposed POPs mixtures by oral gavage twice a week for 6-weeks. At the end of 6-weeks, animals were sacrificed and the hearts were taken for biochemical analysis. Increased activation of the AGE-RAGE signaling cascade via POPs exposure resulted in elevated levels of fibroblast differentiation (α-smooth muscle actin) and RAGE expression indicated maladaptive cardiac remodeling. Conversely, the observed decreased superoxide dismutase-1 and -2 (SOD-1 and SOD-2) expression may exacerbate the adverse changes occurring as a result of POPs treatment to reduce innate cardioprotective mechanisms. In comparison, ventricular collagen levels were decreased in mice exposed to POPs. In conclusion, exposure to organic environmental pollutants may intensify oxidative and inflammatory stressors to overwhelm protective mechanisms allowing for adverse cardiac remodeling.
环境污染物暴露和高饱和脂肪酸饮食的摄入已被证明可促进代谢综合征(高血糖、高胰岛素血症和高三酰甘油血症)的前体形成。本研究的目的是确定暴露于最常见的环境持久性有机污染物(POPs)是否会作为促发因素,促进代谢综合征的发生,而与饮食摄入无关。我们假设 POPs 将激活晚期糖基化终产物(AGE)和 AGE 受体(RAGE)信号级联反应,以促进心脏中心血管重构和氧化应激的下游信号调节剂。在 5 周龄非糖尿病(WT)和糖尿病(ob/ob)小鼠中,通过口服灌胃每周两次暴露于 POP 混合物 6 周。在 6 周结束时,处死动物并取出心脏进行生化分析。通过 POPs 暴露增加 AGE-RAGE 信号级联的激活导致成纤维细胞分化(α-平滑肌肌动蛋白)和 RAGE 表达水平升高,表明心脏重构适应不良。相反,观察到的超氧化物歧化酶-1 和 -2(SOD-1 和 SOD-2)表达降低可能会加剧由于 POPs 治疗而导致的不利变化,从而降低固有心脏保护机制。相比之下,暴露于 POPs 的小鼠心室胶原水平降低。总之,暴露于有机环境污染物可能会加剧氧化和炎症应激,从而破坏保护机制,导致不良的心脏重构。